A heat pipe configuration employing a working fluid in a phase-change thermal cycle to facilitate heat transfer between an evaporator section at one end (where the working fluid is heated to the vapor phase) and a condenser section at the other end (where the working fluid is condensed to the liquid phase) is known. Known heat pipe configurations provide a passage for flow of the vapor phase working fluid from the evaporator section to the condenser section and a passage for flow of the liquid phase working fluid from the condenser section to the evaporator section in a cycle. Such known heat pipe configurations operate in a generally continuous thermal cycle, absorbing heat from a heat source at the evaporator end where the working fluid is heated to vapor phase and rejecting heat at the condenser end where the working fluid is condensed to liquid phase.
It is known to provide a heat pipe in a generally cylindrical form having an exterior shell or wall; the interior of such known heat pipes will typically include for flow of the vapor phase fluid a centralized axial internal passage (for flow from evaporator to condenser) and for flow of the liquid phase fluid an annular or ring-shaped capillary or wick structure (for flow from condenser to evaporator). The central passage and capillary structure together provide the flow circuit for the working fluid during the continuous thermal cycle of operation for the conventional heat pipe.
It is known that within such a heat pipe a pressure differential is developed in the working fluid between the evaporator section (with the working fluid at higher pressure) and the condenser section (with the working fluid at lower pressure); the flow of the (higher pressure) vapor phase working fluid can be directed to perform useful work. It has been disclosed that a heat pipe may be configured to include an internal gas turbine (powered by flow of the vapor phase working fluid) coupled to a generator; such a heat pipe with turbine and generator may be used to produce electricity (i.e. electric power).
However, notwithstanding such known heat pipe configurations, there has not been widespread successful commercial and industrial application of heat pipe configurations for power generation.